Improvement in processes of making bronze-powders



' UNITED STATES PATENT OFFICE.

L. BRANDEIS, on NEW YORK, N. Y.

' IMPROVEM E'NTlN PROCESSES OF MAKING BRONZE-POWDERQ.

Specification forming part of Letters Patent No. 8,365, dated September13, 1851.

. To all whom it may concern:

Be it known that I, LnoPoLn BRANDEIS, in the city of New York, State ofNew York, have 7 invented a new and Improved Mode ofProducingBronze-Powders, by hand, water, steam, or any other power, andgivin g the same a handsome, bright appearance; and I do hereby declarethat the following is a full and exactde scription thereof.

The nature of my invention consists-improducing the powder by rolling itbetween steel or iron tempered rollers, instead of the old producing(kept secret) to beat the mctalto Dutch leaf and grinding it, to give ita bright and brilliant surface by covering the bronzewith soap insteadof grease and oil, and polishing the surface by application of polishedrollers.

Toenable others skilled in the art to make use of my inven tion, Iwillproceed and describe its construction and operation, also the oldproceeding.

. The making of bronze-colors has been parried on in two places inGermany for the last von'ehundred and fifty years, and is still kept asecret there. As Fiirth and Nuremberg, in Bavaria, are-the'only placesin the world where metal-beating is carried on to any great extent, andthe waste of the leaf is used for making bronze, they supplied the wholeknown world. Their expensive process is as follows:

After the metal has been reduced by waterpower to a ribbonof a thinnessof one-sixth of an inch it is beat with iron hammers of twentytwo poundseach till about one-twelfth of an inch thick, annealed, cut in squarepieces of one and a. half inch, laid between parchment, and

'beat two hours. Then it is taken out, annealed after wrapping it up ina stout piece of rolled brass, cooled between sand, cleaned, and cutagain in square inch pieces. Then it is filled inthe gold-heaters skinsand'beat until reduced to the thin leaf, commonly called Dutch or metalleaf. The cuttings and waste leaf are used now for grindin g, after itwas brushed through a sieve. Then it is washed out, moved slowly andequally for an hour to settle the metallic parts on the bottom of abasin containing six pounds, then dried. For giving it brilliancy and toprotect it against the infiuence of air, they cover it with grease overa coal-fire. Some even grind 'it with oil and take the superfluous oiloutagain by hydraulic pressure.

Y My proceeding-is; I take ship-metal(sheeting) or any other-rolledcopper or composition of copper,,zinc, and tin, break this down by ironor steel rollers to a powder, mix this with gum-arabic and water, grindit anhour, wash it out, and dryit. After this I takehalf an ounce ofwhite Windsor or any other white I soap, scrape it under the bronzc,pass the mix- 2. The application and manner of application of soap tomake the bronze bright and brilliant and durable. V

' BRA NDEIS.

Witnesses: l

L, WICKERT, D. NEWMANN.

